REPORT ON HARDISTY CREEK RESTORATION PROJECT HARDISTY AVENUE CULVERT BACKFLOODING RIFFLE CONSTRUCTION Submitted to: Athabasca Bioregional Society Box 5058 Hinton, Alberta, T7V 1X3 DISTRIBUTION: 2 Copies Athabasca Bioregional Society Hinton, Alberta 1 Copy Golder Associates Ltd. Edmonton, Alberta January 2007 05-1373-029
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REPORT ON
HARDISTY CREEK RESTORATION PROJECTHARDISTY AVENUE CULVERT
BACKFLOODING RIFFLE CONSTRUCTION
Submitted to:
Athabasca Bioregional SocietyBox 5058
Hinton, Alberta, T7V 1X3
DISTRIBUTION:
2 Copies Athabasca Bioregional SocietyHinton, Alberta
1 Copy Golder Associates Ltd.Edmonton, Alberta
January 2007 05-1373-029
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EXECUTIVE SUMMARY
Introduction
In October 2003, Golder Associates Ltd. (Golder) was retained by Foothills Model Forest on
behalf of the Hardisty Creek Restoration Project (HCRP) to undertake an assessment of fish
passage and habitat restoration opportunities on Hardisty Creek, in and near Hinton, Alberta. The
results of this study (Golder 2004) recommended riffle restoration and culvert backflooding in the
Kinsmen Park reach of Hardisty Creek, between Hardisty Avenue and Switzer Drive.
The initial habitat restoration in the Kinsmen Park reach was undertaken in October 2004, and
included construction of eight rock riffles, large woody debris (LWD) placement and woody
plantings. The upper rock riffle, intended to backflood the Hardisty Avenue culverts for fish
passage, was not constructed at that time due to budget limitations.
This report describes the construction of the upper riffle, which was constructed in October 2005.
It documents the detailed design and permitting for the upper riffle construction, the construction
methods, sequence and environmental monitoring. The report also provides an assessment of the
stability of Large Woody Debris (LWD) structures installed in 2004, a preliminary assessment of
restoration alternatives for the reach of Hardisty Creek below Switzer Drive, and a description of
maintenance to the lower riffles in the Kinsmen Park reach of Hardisty Creek.
Detailed Design
A conceptual-level design for backflooding of the Hardisty Avenue culverts was presented in a
previous report (Golder 2004). The design was intended to meet the goal of reducing the mean
flow velocities through the culverts to 1 m/s or less, at discharges of 1.6 m3/s or less. This would
allow passage of fish with swimming modes similar to rainbow trout, bull trout and similar
salmonids. During final design of the riffle, its crest elevation was modified slightly reduce the
downstream gradient and its cross-slope was reduced to create a shallower, slower and less
erosive flow along the downstream face of the riffle. The design slope of the downstream face of
the riffle was steepened slightly to prevent the toe of the riffle from reaching the next downstream
riffle, and two equally-spaced rock vortex weirs and random boulder placement were added to the
downstream face of the riffle for additional grade control.
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The final design for the riffle specified 150 mm minus pit run gravel for use as general fill,
350 mm minus rock fill to provide an armored surface for the riffle, and 750 mm diameter rock
riprap for construction of the riffle crest, vortex weirs and random boulder placement. Additional
materials included impermeable liner and non-woven geotextile installed as a seepage barrier
below the riffle crest and live willow stakes installed in selected locations around the riffle and
upstream pool.
It must be noted that though the riffle structure is designed to withstand a flood with a 100-year
return period, it will not necessarily be maintenance free. Natural transport of bed material would
convey sands and gravels from upstream across the riffle and downstream during high flows. The
presence of the upstream culverts and deep pool could potentially limit the availability of material
from upstream and prevent replacement of smaller material on the face of the riffle. Periodic
monitoring of the riffle is recommended to identify potential future maintenance requirements.
Monitoring should evaluate in-filling of the culvert outlet pool and scour of small material from
the face of the riffle.
Permitting
The stream restoration works described here were performed in accordance with Alberta Water
Act Approval #00211360, Canada Fisheries Act Authorization #ED-04-2284, and the Fish
Collection License held by Foothills Model Forest. Copies of the relevant permits are provided in
Appendix I.
The Fisheries Act Authorization requires that a “post-construction assessment of the project area
shall be conducted and submitted to DFO in the fall of 2006 to identify any problem areas that
require remedial action. The program shall assess the physical stability of the new streambed,
instream remediation prescriptions, and of the creek and banks for 500m upstream and 500m
downstream of the works. Fish passage shall also be assessed. Post-construction monitoring
reports including photos shall be submitted to DFO, referencing file #ED-04-2284, within one
year following completion of the works. The monitoring report shall also include photographic
documentation on the survival of riparian vegetation plantings. If less that 85% of the vegetation
survives, then the Town of Hinton shall replace the lost vegetation.”
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Construction
Construction took place between 10 October and 14 October 2005. It involved participation of
the Town of Hinton, the Athabasca Bioregional Society, Foothills Model Forest, Big Berland
Construction, West Central Construction, Westridge Sand & Gravel, Golder Associates,
Millennium EMS and Hoitsma Ecological.
Prior to the start of instream construction, the Town of Hinton stockpiled 150 mm minus gravel in
the parking lot adjacent to the works. On 10 October 2005, Golder Associates and Millennium
EMS personnel performed construction layout surveys and a fish salvage at the site.
On 11 October 2005, instream construction commenced. A flow diversion channel was
constructed, 150 mm minus fill was placed in the dry channel and the impermeable liner,
geotextile and rock riprap were placed at the riffle crest.
On 12 October 2005, additional 150 mm minus fill was placed and rock riprap was hauled to the
site and placed at the riffle crest and at the two vortex weirs.
On 13 October 2005, additional 150 mm minus fill was placed and 350 mm minus armor material
was hauled and placed. Rock riprap and 350 mm minus armor material were moved to the lower
riffles for maintenance.
On 14 October 2005, a buried diversion pipe was placed to allow full-width construction of the
riffle. Woody plantings were placed along the edges of the riffle and upstream pool. The riffle
was completed by late afternoon with the exception of a small amount of fill on the LDB at the
lower end of the riffle. Material was stockpiled at this location and the work was subsequently
completed by a local contractor with a skid steer loader (Buttazoni).
Environmental Monitoring
Environmental monitoring included a fish salvage prior to commencement of instream works and
turbidity monitoring during construction. Detailed fish salvage data are provided in Appendix III
and turbidity monitoring data are provided in Appendix IV.
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Additional Issues
Ballasting of LWD structures installed in 2004 were assessed for stability. The detailed analysis
is provided in Appendix V, which indicates that 10 of the 20 structures can be classified as stable.
The analysis did not confirm stability for the remaining structures, though the analysis method is
likely conservative and it must be noted that there did not appear to be any movement of these
structures during the high water events of June 2005. For structures that are potentially
underballasted, dimensions and calculations should be confirmed after an additional inspection to
confirm the parameters used in the assessment, and additional ballasting should be considered if
required.
Hardisty Creek Below Switzer Drive is currently being considered for restoration as part of the
next phase of the Hardisty Creek Restoration Project. A site reconnaissance indicated that the
channel in this area has little or no floodplain area and it appears that fill has been placed on the
left and right overbanks to increase the area available to commercial developments on either side
of Hardisty Creek. The channel in this area would benefit from excavation in the overbank area
to provide an adequate floodplain, and that revegetation with native species and placement of
natural materials for grade and erosion control, rather than the concrete rubble that currently
exists in several locations, would be beneficial.
A seep of a hydrocarbon or chemical substance was observed at one location on the LDB of the
creek, and waste, including pieces of metal, were observed in fill on both banks. It is
recommended that, as a minimum, a Phase I Environmental Site Assessment be undertaken on
this site prior to construction of any stream restoration works that could potentially expose
contaminated soils.
Lower Riffle Maintenance and Improvement included replacement of rock riprap boulders and
additional placement of small boulder and cobble material from the 350 mm minus fill material
available on site. Materials were stockpiled on the RDB at each riffle for future placement by
community volunteers, and at some riffles, material was hand placed. The preferred placement
method is to place the largest material first, in the area below the existing boulders, and then
place smaller boulders and cobbles to bridge the gaps and create a rock matrix that will eventually
trap smaller fractions that are carried down the creek.
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TABLE OF CONTENTS
SECTION PAGE
1. INTRODUCTION .....................................................................................................................11.1 Background .........................................................................................................................11.2 Organization of the Report ..................................................................................................1
3. CONSTRUCTION.....................................................................................................................73.1 Methods and Construction Sequence ..................................................................................7
3.1.1 Pre-Construction Staging ..........................................................................................73.1.2 11 October 2005........................................................................................................73.1.3 12 October 2005........................................................................................................83.1.4 13 October 2005........................................................................................................83.1.5 14 October 2005........................................................................................................9
3.2 Environmental Monitoring ................................................................................................103.2.1 Fish..........................................................................................................................103.2.2 Sediment and Turbidity...........................................................................................11
Table 1 – Riffle Armor Layer Sizing Calculations...........................................................................5Table 2 – Regulatory Permits for Stream Restoration Works ..........................................................6Table 3 – Summary of Calculated Factors of Safety for LWD Structures .....................................13
LIST OF FIGURES
Figure 1 – Profile View Showing Riffle Design ..............................................................................3Figure 2 – Elevation View Showing Riffle Design..........................................................................3Figure 3 – Turbidity Monitoring at Switzer Drive and at Upstream Background Site ..................12
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LIST OF APPENDICES
Appendix I Regulatory Permits for Instream ConstructionAppendix II PhotographsAppendix III Fisheries Information Collected Prior to ConstructionAppendix IV Turbidity Data Collected During ConstructionAppendix V LWD Ballasting AssessmentAppendix VI Construction Survey DataAppendix VII July 2006 Inspection and Photo SurveyAppendix VIII Review Comments on Draft Report
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1. INTRODUCTION
1.1 Background
In October 2003, Golder Associates Ltd. (Golder) was retained by Foothills Model Forest on
behalf of the Hardisty Creek Restoration Project (HCRP) to undertake an assessment of fish
passage and habitat restoration opportunities on Hardisty Creek, in and near Hinton, Alberta. The
results of this study (Golder 2004) recommended riffle restoration and culvert backflooding in the
Kinsmen Park reach of Hardisty Creek, between Hardisty Avenue and Switzer Drive.
The initial habitat restoration in the Kinsmen Park reach was undertaken in October 2004, and
included construction of eight rock riffles, large woody debris (LWD) placement and woody
plantings. The upper rock riffle, intended to backflood the Hardisty Avenue culverts for fish
passage, was not constructed at that time due to budget limitations.
This report describes the construction of the upper riffle, which was constructed in October 2005.
1.2 Organization of the Report
Chapter 2 of this report describes pre-construction activities, including detailed design (geometry
and materials) and permitting for the project.
Chapter 3 of the report describes activities taking place during the construction period, including
construction methods and sequence. It also describes environmental monitoring activities
undertaken for regulatory compliance.
Chapter 4 of the report describes additional issues related to the project. These include an
assessment of the stability of LWD structures installed on Hardisty Creek in 2004, and a
reconnaissance of the reach of Hardisty Creek immediately below Switzer Drive, which could
potentially be restored in the next phase of the project.
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2. PRECONSTRUCTION
2.1 Design
2.1.1 Riffle Geometry
A conceptual-level design for backflooding of the Hardisty Avenue culverts was presented in a
previous report (Golder 2004). The design was intended to meet the goal of reducing the mean
flow velocities through the culverts to 1 m/s or less, at discharges of 1.6 m3/s or less. This would
allow passage of fish with swimming modes similar to rainbow trout, bull trout and similar
salmonids. It considered a riffle vertex crest elevation of 101.00 m, referenced to the large
culvert outlet invert elevation of 100.00 m. The riffle crest rose at a design slope of 6H:1V from
the riffle vertex towards each bank. The upstream face of the riffle had a design slope of 4H:1V
and the downstream face of the riffle had a design slope of 20H:1V.
During final design of the riffle, the crest vertex elevation was reduced by 0.10 m to 100.90 m to
slightly reduce the downstream gradient. The design slope of the riffle crest from vertex to each
bank was changed from 6H:1V to 20H:1V to reduce the concentrated flow over the riffle crest
and along its downstream face. This will result in a shallower, slower and less erosive flow along
the downstream face of the riffle. The design slope of the upstream face of the riffle was
unchanged at 4H:1V. The design slope of the downstream face of the riffle was steepened
slightly from 20H:1V to 14H:1V to prevent the toe of the riffle from reaching the next
downstream riffle (Riffle #2). The effects of this steeper slope of approximately 7% were offset
by adding two equally-spaced rock vortex weirs and random boulder placement on the
downstream face of the riffle.
Profile and elevation views showing the design of Riffle #1 are shown in Figures 1 and 2,
respectively.
2.1.2 Riffle Materials
The final design for the riffle considered the following materials:
ThalwegCulvert InvertDesign ThalwegDesign Top of PitrunUpstream Riffle Crest RockDownstream Riffle Crest RockImpermeable Liner
Figure 1 – Profile View Showing Riffle Design
Figure 2 – Elevation View Showing Riffle Design
98.5
99.0
99.5
100.0
100.5
101.0
101.5
102.0
102.5
0 5 10 15 20 25 30
Distance from RDB Reference Point (m)
Ele
vati
on
(m;
Lo
calD
atu
m)
Pre-Construction Bed Elevation
Design Riffle Crest Elevation
Design top of 150 mm minus Fill
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150 mm minus rock fill material was used to bring the existing bed elevation up in the core
of the riffle. This was placed below the armor layer off the riffle and creek bed and
comprised a well-graded mix of cobble, gravel, sand and silt. This material was provided as
a contribution from the Town of Hinton and quantities were stockpiled on site prior to the
start of construction;
350 mm minus rock fill material was used for the upper armor layer of the riffle and creek
bed and comprised a well-graded mix of boulder, cobble, gravel, sand and silt. The upper
armor layer was placed to a thickness of 500 mm. Some of this material was also placed at
the lower riffles to provide supply for future maintenance and improvement, as discussed in
Section 4.3. It was hoped that this material could be sourced from the concurrent East
Hardisty sewer project construction (refer to Photographs 21 and 22 in Appendix II). This
material proved to be unavailable in sufficient quantity, so other sources were considered,
including the West Central yard in Hinton (refer to Photograph 23 in Appendix II), the West
Central Pit across the Athabasca River from Hinton (refer to Photographs 24 to 26 in
Appendix II), and a Town of Hinton waste rock pile (refer to Photograph 33 in Appendix II).
None of these sources could provide large enough material. Adequately sized material was
eventually purchased from the Border Paving pit in Hinton (refer to Photographs 38 to 42
and 51 in Appendix II), and a small quantity of 250 to 300 mm rock was also purchased from
Northland Maintenance and transported from their stockpile at the Town of Hinton yard;
750 mm diameter rock riprap was placed as a double row along the riffle crest, in the two
vortex weirs on the downstream face of the riffle, in random locations on the downstream
face of the riffle, and as additional protection against flow impingement along the upstream
face of the riffle. Some of this material was also placed at the lower riffles to provide supply
for future maintenance and improvement, as discussed in Section 4.3. The source of this
material included salvage material from that placed at Riffle #1 in 2004 and a small quantity
of material purchased from Northland Maintenance. The bulk of the rock riprap was
purchased from the Border Paving pit in Hinton. This material can be seen in Photograph
20, among others, in Appendix II;
Impermeable liner material, fish-friendly with a thickness of 30 mil, and non-woven
geotextile were purchased from Nilex Geosynthetics in Edmonton. This material was placed
vertically, below the crest of Riffle #1, to discourage subsurface flow through the riffle. The
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material and its placement are shown in Photographs 10 and 13 to 15 in Appendix II. Non-
woven geotextile was also placed along the upstream face of the footer stones in each vortex
weir, as shown in Photograph 35 in Appendix II; and
Live willow stakes were also placed in selected locations along Riffle #1, under the
direction of Todd Hoitsma of Hoitsma Ecological. These stakes were locally sourced by
Connie Bresnahan of the Athabasca Bioregional Society. The willow staking is shown in
Photographs 60 and 61, 95 and 96, 103, 112 and 113 in Appendix II.
The specified 350 mm minus armor material was expected to have a d50 of approximately
200 mm. To check on the erodibility of this material, critical velocities corresponding to design
flow depths at the riffle were calculated according to a sediment transport equation presented by
Melville and Coleman (2000). In the equation shown below, the critical velocity for sediment
entrainment, Vc, is a function of the flow depth, y, and median particle diameter, d50:
Vc = 5.67y1/6d501/3
Maximum flow depths and mean flow velocities along the downstream face of the riffle were
calculated based on the design discharges corresponding to return periods of 2, 25 and 100 years.
The calculations summarized in Table 1 are based on the riffle geometry described in Section
2.1.1 and show that during the 100-year flood, bed material with a d50 of 0.200 m (corresponding
to the 350 minus material used for this project) should be stable to a critical velocity of 3.0 m/s.
This is greater than the calculated mean flow velocity of 2.2 m/s and should provide some factor
of safety. Calculated critical velocities for smaller armor material sizes are provided for
comparison purposes.
Table 1 – Riffle Armor Layer Sizing Calculations
Median particle diameter (m)
0.200 0.150 0.100 0.075
ReturnPeriod
DesignDischarge,Q (m3/s)
MaximumFlow Depth,
y (m)
Mean FlowVelocity,V (m/s)
Vcritical
(m/s)Vcritical
(m/s)Vcritical
(m/s)Vcritical
(m/s)
2 year 2.3 0.28 1.4 2.7 2.4 2.1 1.9
25 year 7.8 0.45 2.0 2.9 2.6 2.3 2.1
100 year 11.8 0.52 2.2 3.0 2.7 2.4 2.1
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It must be noted that though the riffle structure is designed to withstand a flood with a 100-year
return period, it will not necessarily be maintenance free. Natural transport of bed material would
convey sands and gravels from upstream across the riffle and downstream during high flows. The
presence of the upstream culverts and deep pool could potentially limit the availability of material
from upstream and prevent replacement of smaller material on the face of the riffle. Periodic
monitoring of the riffle is recommended to identify potential future maintenance requirements.
2.2 Permitting
The stream restoration works described here were performed under the authorizations and
approvals described in Table 2. Copies of the relevant permits are provided in Appendix I.
Table 2 – Regulatory Permits for Stream Restoration Works
Legislation Administered By Permit
AlbertaWater Act
Alberta Environment (AENV) Approval #00211360, amended27 September 2005
CanadaFisheries Act
Alberta Sustainable ResourcesDevelopment (ASRD)
FMF Research Fish Collection License
CanadaFisheries Act
Fisheries and Oceans Canada(DFO)
Authorization #ED-04-2284, amended29 September 2005
The Alberta Water Act Approval requires the approval holder submit a Certificate of Completion
to Alberta Environment when the activity is completed.
The Fisheries Act Authorization requires that a “post-construction assessment of the project area
shall be conducted and submitted to DFO in the fall of 2006 to identify any problem areas that
require remedial action. The program shall assess the physical stability of the new streambed,
instream remediation prescriptions, and of the creek and banks for 500m upstream and 500m
downstream of the works. Fish passage shall also be assessed. Post-construction monitoring
reports including photos shall be submitted to DFO, referencing file #ED-04-2284, within one
year following completion of the works. The monitoring report shall also include photographic
documentation on the survival of riparian vegetation plantings. If less that 85% of the vegetation
survives, then the Town of Hinton shall replace the lost vegetation.”
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3. CONSTRUCTION
3.1 Methods and Construction Sequence
3.1.1 Pre-Construction Staging
Prior to construction, the Town of Hinton stockpiled approximately 400 m3 of 150 mm minus
gravel in the parking lot adjacent to the works.
3.1.2 11 October 2005
On the first day of construction, equipment used included a Komatsu PC200LC excavator with
thumb (Big Berland Construction) and John Deere 240 skid steer loader (Town of Hinton). The
sequence of construction included:
An instream diversion was constructed on the left downstream bank (LDB) of the channel
by excavating a dry, shallow trench, lining it with polyethylene, and then blocking off the
remainder of the channel with 150 mm minus fill (refer to photographs 6 to 8 and 19 in
Appendix II);
150 mm minus was placed to raise the channel bed elevation. This was done “in the dry”
by moving stockpiled material to the right downstream bank with the skid steer loader
and placing it with the excavator (refer to photographs 11, 12 and 18 in Appendix II).
The fill was compacted by tracking and/or compression with the excavator bucket;
An impermeable liner was placed below the riffle crest, by stapling it to 2 x 4 support
posts. Fill was placed incrementally on each side of the liner to prevent its displacement
(refer to photographs 10 and 13 to 15 in Appendix II); and
750 mm rock riprap was placed at the riffle crest (refer to photographs 16 and 20 in
Appendix II).
On the afternoon of 11 October, potential sources of 350 mm minus armor material were
investigated, including the Hinton East Hardisty sewer excavation (refer to photographs 21 and
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22 in Appendix II), the West Central Hinton yard (refer to photograph 23 in Appendix II), and the
West Central pit (refer to photographs 24 to 26 in Appendix II).
3.1.3 12 October 2005
On the second day of construction, use of the Big Berland Construction excavator and Town of
Hinton skid steer loader continued. In addition to this, Town of Hinton and West Central dump
trucks were used to transport materials, an additional excavator (Westridge Sand & Gravel) was
used to load rock riprap at the Border Paving pit, and a John Deere 544 articulated loader (Town
of Hinton) was used to load 150 mm minus material at the Town of Hinton yard. The sequence
of construction included:
Placement of 150 mm minus fill continued;
Approximately 80 pieces of 750 mm minus rock riprap, approximately 10 additional
loads of 150 mm minus material, and small quantities of rock riprap and small boulders
purchased from Northland Maintenance were hauled to the project site; and
750 mm minus rock riprap was placed at the riffle crest and upstream face, as well as at
the lower of two rock weirs (refer to photograph 35 in Appendix II).
On the afternoon of 12 October, it became apparent that the Hinton East Hardisty sewer
excavation would not be able to provide 350 mm minus armor material to the project, and two
additional potential sources were investigated. These included the Town of Hinton waste
stockpile (refer to photograph 33 in Appendix II) and the Border Paving Hinton pit (refer to
photograph 38 in Appendix II).
3.1.4 13 October 2005
On the third day of construction, use of the Big Berland Construction excavator and Town of
Hinton skid steer loader continued. In addition to this, Town of Hinton and West Central dump
trucks were used to transport materials, and the Town of Hinton articulated loader was moved to
the work site to move stockpiled materials into the work area. The sequence of construction
included:
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350 mm minus armor material from the Border Paving Hinton Pit was hauled to the site
and stockpiled (refer to photographs 39 to 42 and 51 in Appendix II);
Placement of 150 mm minus fill continued and placement of 350 mm minus fill
commenced (refer to photographs 47 to 50 and 52 to 56 in Appendix II);
The skid steer loader was used to haul rock riprap and some 350 mm minus material for
lower riffle maintenance (refer to photographs 29 to 32), while the larger loader was used
at the upper riffle; and
A sediment trap was installed at the downstream end of Kinsmen Park, in anticipation of
mobilizing more sediment during riffle construction (refer to photographs 43 to 46 in
Appendix II).
By the end of the day on 13 October, it became apparent that the two 4-inch pumps that were
being used in tandem with the instream flow diversion would not be sufficient to convey all flow
when fill was placed along the LDB, in the instream diversion area. Four lengths of 500 mm
diameter “Big O” pipe were purchased from UMA Engineering in Hinton and transported to the
work site to be used as a temporary buried diversion pipe.
3.1.5 14 October 2005
On the fourth day of construction, use of the Big Berland Construction excavator and Town of
Hinton skid steer and articulated loaders continued. The sequence of construction included:
Placement of the 500 mm “Big O” diversion pipe and placement of 150 mm minus fill on
top of it (refer to photographs 57 to 68 in Appendix II);
Placement of 350 mm minus armor material and rock riprap at lower riffles for
maintenance (refer to photographs 70 to 76 in Appendix II);
The skid steer loader was used to haul rock riprap and some 350 mm minus material for
lower riffle maintenance (refer to photographs 29 to 32), while the larger loader was used
at the upper riffle;
Continued placement of 350 minus armor material and 750 mm rock riprap in the riffle
and two vortex weirs. As lower surfaces were completed, the pumped diversion hoses
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were placed to discharge on the armor layer to enhance the movement of fines
downwards into the rock matrix (refer to photographs 97 to 104 in Appendix II);
The inlet of the diversion pipe was blocked with filter fabric, rock riprap and 150 mm
minus fill and the riffle crest was completed (refer to photographs 105 to 109 and 114 to
119 in Appendix II); and
Woody plantings were placed along the LDB and RDB along the length of the riffle and
in the upstream pool, under the direction of Todd Hoitsma of Hoitsma Ecological Inc.
(refer to photographs 112 and 113 in Appendix II).
At the end of the day on 14 October, construction was complete with the exception of a small
amount of fill on the LDB at the lower end of the riffle. Material was stockpiled at this location
and the work was subsequently completed by a local contractor with a skid steer loader
(Buttazoni). The completed riffle is shown in photographs 120 to 122 and 124 to 126 in
Appendix II.
3.2 Environmental Monitoring
3.2.1 Fish
Prior to construction, on the evening of 11 October 2005, block nets were set approximately 10 m
above the Hardisty Avenue culverts and immediately above Riffle #3, approximately 60 m
downstream of the Hardisty Avenue culvert outlets. This area was electrofished by Golder
Associates Ltd. and Millennium EMS Ltd. personnel on the evening of 10 October 2005 and was
subsequently electrofished by Foothills Model Forest personnel on the morning of 11 October
2005, before the commencement of instream work. A record of fish collected during these fish-
outs is provided in Appendix III and was provided to Alberta Sustainable Resources Development
in compliance with the terms of the Fish Collection License. Several of the largest fish salvaged
during the fish-out on 10 October 2005 are shown in Photographs 1 to 5 in Appendix II.
On the morning of 11 October 2005, prior to electrofishing, the lower block net was moved to just
above Riffle #3, as shown in Photograph 76 in Appendix II. The block nets were removed after
construction, at approximately 1800h on 14 October 2005.
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3.2.2 Sediment and Turbidity
It is not possible to reconstruct a creek bed without releasing some sediment into the creek.
Placing “clean” material, without fines, would leave voids between larger rock fractions, allowing
flow through the rock matrix and resulting in subsurface flow during low flow periods. Indeed,
this was thought to be a problem in several parts of the creek in its Kinsmen Park reach, prior to
the stream restoration. Three types of material were placed in the creek during construction of the
Riffle #1. These included:
clean rock riprap, used as armor for riffle and vortex weir crests;
350 mm minus fill material. This was used for the upper armor layer of the riffle and
creek bed and comprised a well-graded mix of boulder, cobble, gravel, sand and silt.
This material was exposed to flow immediately after construction and fines entered the
creek during the “first flush” of flow over this material; and
150 mm minus fill material. This was used as fill below the armor layer off the riffle and
creek bed and comprised a well-graded mix of cobble, gravel, sand and silt. This
material was completely covered with 350 mm minus fill material material and is not
intended to ever be exposed to flow.
During instream construction, from 11 October to 14 October 2005, turbidity was monitored at
the lower end of the Kinsmen Park reach, at Switzer Drive. The results of turbidity monitoring
are plotted in Figure 1 and detailed data are presented in Appendix IV. Most readings during
construction fell below 25 NTU, with the exception of single-measurement spikes during the late
mornings of 12 October and 14 October, and during the “first flush” period on the afternoon of
14 October, when the armor fill was first exposed to flow.
A sediment trap was installed on Hardisty Creek, just above Switzer Drive, on the morning of
13 October, prior to the “first flush” and remained in place until approximately 1800h on 14
October, approximately 3 hours after the initial pulse of sediment from the introduction of flow to
Riffle #1. The sediment trap is shown in Photographs 43 to 46, 52 to 56, 69 and 94 in
Appendix II.
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0
20
40
60
80
100
120
140
160
Oct 10 12:00 Oct 11 12:00 Oct 12 12:00 Oct 13 12:00 Oct 14 12:00 Oct 15 12:00Date and Time
Tu
rbid
ity
Rea
din
g(N
TU
)Turbidity Measured at Switzer DriveUpstream Background TurbidityInstream Work Period
Start of ConstructionWith Instream Diversion
Sediment TrapInstalled at Switzer Drive
Diversion PipeInstalled
First Flush of ChannelBed Armor Material
Instream WorkCompleted
Sediment Trap atSwitzer Drive Removed
Figure 3 – Turbidity Monitoring at Switzer Drive and at Upstream Background Site
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4. ADDITIONAL ISSUES
4.1 LWD Installed in 2004
A detailed analysis of ballasting for the Large Woody Debris (LWD) structures installed in 2004
is provided in Appendix V, and a summary of the calculations is provided in Table 3, along with
comments and recommendations for each structure. Overall, stability was confirmed for 10 of the
20 LWD structures. The remaining structures had calculated Factors of Safety for Buoyancy,
FSB, of between 0.4 and 1.1. LWD structures with FSB values of 1.0 or less by definition will
have Factors of Safety for Sliding, FSS, of less than zero. These structures may be underballasted;
however, it is possible in some cases that the calculated values are overly conservative. This is
because the ballasting calculations assume full submergence of the LWD structures, and the
relatively low water depths during flood events on Hardisty Creek mean that logs may not be
fully submerged. There did not appear to be any movement of these structures during the high
water events of June 2005.
Table 3 – Summary of Calculated Factors of Safety for LWD Structures
LWDStructure
Factor ofSafety forBuoyancy,
FSB
Factor ofSafety forSliding,
FSS
Comments and Recommendations
1 0.4 -2.5 Confirm dimensions; may be underballasted.
2 4.4 3.1 Stability confirmed.
3 2.2 n/a Stability confirmed.
4 2.3 1.3 Stability confirmed.
5 1.6 1.6 Likely stable, FS > 2.0 would be preferred.
6 2.5 n/a Stability confirmed.
7 0.9 -0.1 Confirm dimensions; may be underballasted.
8 3.7 2.1 Stability confirmed.
9 2.3 n/a Stability confirmed.
10 0.7 n/a Confirm dimensions; may be underballasted.
11 1.1 0.3 May be underballasted but appeared stable in June 2005.
12 1.0 -0.1 Confirm dimensions; may be underballasted.
13 1.8 n/a Likely stable, FS > 2.0 would be preferred.
14 0.6 -2.3 Confirm dimensions; may be underballasted.
15 0.7 -0.8 Confirm dimensions; may be underballasted.
16 2.2 3.3 Stability confirmed.
17 0.9 -0.4 Confirm dimensions; may be underballasted.
18 0.7 -1.4 Calculations say underballasted, but currently embedded in bed.
19 0.6 n/a Confirm dimensions; may be underballasted.
20 3.2, 2.2, 1.3 2.4, 1.2, 1.1 Likely stable, FS > 2.0 would be preferred.
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For structures that are potentially underballasted, dimensions and calculations should be
confirmed after an additional inspection to confirm the parameters used in the assessment, and
additional ballasting should be considered if required.
4.2 Future Restoration Below Switzer Drive
The reach of Hardisty Creek located below Switzer Drive and above the West Fraser property is
currently being considered for restoration as part of the next phase of the Hardisty Creek
Restoration Project. On the morning of 14 October 2005, a site reconnaissance of this area was
undertaken by Nathan Schmidt of Golder Associates Ltd. and Todd Hoitsma of Hoitsma
Ecological Inc. Photographs 77 to 93 in Appendix II were taken during this reconnaissance.
The channel in this area has little or no floodplain area and it appears that fill has been placed on
the left and right overbanks to increase the area available to commercial developments on either
side of Hardisty Creek. It was agreed that the channel in this area would benefit from excavation
in the overbank area to provide an adequate floodplain, and that revegetation with native species
and placement of natural materials for grade and erosion control, rather than the concrete rubble
that currently exists in several locations, would be beneficial.
A seep of a hydrocarbon or chemical substance was observed on the LDB of the creek, as shown
in Photograph 87 in Appendix II. Waste, including pieces of metal, was observed in fill on both
banks, as shown in Photographs 85 and 93. It is recommended that, as a minimum, a Phase I
Environmental Site Assessment be undertaken on this site prior to construction of any stream
restoration works that could potentially expose contaminated soils.
4.3 Lower Riffle Maintenance and Improvement
A site reconnaissance undertaken on 20 August 2005 showed that some undersized cobble-gravel
material that had been used to construct the downstream faces of the lower riffles (Riffle #2
through Riffle #9) on Hardisty Creek had been washed away during summer floods. In some
locations, scouring of gravel from below the riffle resulted in toppling of riffle boulders and
downstream movement. The pre-construction condition of each riffle is shown in Photographs
The recommended remedial action was replacement of rock riprap boulders and additional
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placement of small boulder and cobble material from the 350 mm minus fill material available on
site.
Some maintenance was performed at Riffle #2 using the excavator while it was working at the
lower end of Riffle #1. Equipment access to the lower riffles (Riffle #3 to Riffle #9) was limited
because of height restrictions on land and the desire not to walk the tracked excavator across
existing riffles. At these riffles, 350 minus material was stockpiled on the RDB for future
placement by community volunteers, as shown in Photographs 70 to 76 in Appendix II. Material
was hand placed at Riffle #8, as shown in Photographs 30 to 32 in Appendix II. The preferred
placement method is to place the largest material first, in the area below the existing boulders,
and then place smaller boulders and cobbles to bridge the gaps and create a rock matrix that will
eventually trap smaller fractions that are carried down the creek.
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5. CONCLUSION
This report documents the detailed design and construction of the upper riffle in the Kinsmen
Park reach of Hardisty Creek, which was built in October 2005. It also presents additional
assessments of the LWD structures that were installed in October 2004, of the potential future
restoration area below Switzer Drive, and of the maintenance activities prescribed for the lower
riffles in the Kinsmen Park reach.
We trust the above meets your present requirements. If you have any questions or require
additional details, please contact the undersigned.
GOLDER ASSOCIATES LTD.
Nathan Schmidt, Ph.D., P.Eng.Associate, Senior Water Resources Engineer
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6. REFERENCES
D’Aoust, S.G. and R.G. Millar. 1999. Large Woody Debris Fish Habitat Structure Performance
and Ballasting Requirements. British Columbia Ministry of Water, Land and Air
Protection, Watershed Restoration Management Report No. 8, 119 p.
Golder 2004. Hardisty Creek Fish Habitat and Fish Passage Assessments and Corrective
Designs. Prepared by Golder Associates Ltd. for Foothills Model Forest, May 2004, 56 p.
Melville, B.W. and S.E. Coleman. 2000. Bridge Scour. Water Resources Publications, LLC,
Highlands Ranch, Colorado, 550 p.
Slaney, P.A. and D. Zaldokas, eds. 1997. Fish habitat rehabilitation procedures. Watershed
Restoration Technical Circular No. 9. Watershed Restoration Program, Ministry of
Environment, Lands and Parks, Vancouver, B.C.
APPENDIX I
REGULATORY PERMITS FORINSTREAM CONSTRUCTION
APPENDIX II
PHOTOGRAPHS
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Photograph Description
Photograph 1: 10-Oct-05 1712h
222 mm long Rainbow Trout (RNTR) salvaged during the fish-outon the evening prior to construction.
Photograph 2: 10-Oct-05 1713h
190 mm long Brook Trout (BRTR) salvaged during the fish-out onthe evening prior to construction.
Photograph 3: 10-Oct-05 1713h
168 mm long Bull Trout (BLTR) salvaged during the fish-out onthe evening prior to construction.
Photograph 4: 10-Oct-05 1714h
87 mm long Mountain Whitefish (MNWH) salvaged during the fish-out on the evening prior to construction.
Photograph 5: 10-Oct-05 1715h
200 mm long Bull Trout (BLTR) salvaged during the fish-out onthe evening prior to construction.
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Photograph Description
Photograph 6: 11-Oct-05 0809h
View of left downstream bank (LDB) diversion from upstream.The temporary diversion was lined with heavy polyethylene andwas completely within the existing channel.
Photograph 7: 11-Oct-05 0823h
Placement of fill at upstream riffle to bring up the water level in theupstream pool and to force all flow through the instream diversion.
Photograph 8: 11-Oct-05 0833h
Minor excavation at the upper end of the diversion to enhanceflow through the diversion.
Photograph 9: 11-Oct-05 0854h
Movement of 150 mm minus granular fill material with the Town ofHinton bobcat. The material was moved from the stockpile in theKinsmen Park parking lot to the edge of the creek bank, to allowthe excavator to reach it without climbing out of the channel.
Photograph 10: 11-Oct-05 0920h
Photograph of the impermeable liner used in the upstream riffle.This material was fish-friendly non-woven geotextile was placedagainst it on the downstream side to provide some protectionagainst rock during placement.
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Photograph Description
Photograph 11: 11-Oct-05 0923h
Placement of 150 mm minus granular fill material below theupstream riffle. A small amount of flow through the rightdownstream bank (RDB) area remained after construction of theinstream diversion, and the initial placement of this material wasused to block all flow through the area outside of the diversion. Allpractical efforts were made to prevent water from flowing againstthis material to prevent erosion and transport of sediment into thedownstream reach of Hardisty Creek.
Photograph 12: 11-Oct-05 0952h
This picture shows complete diversion of flow through theinstream diversion. Some rock riprap has been placed against theupstream portion of the upper riffle.
Photograph 13: 11-Oct-05 1025h
The impermeable liner and accompanying non-woven geotextilewere initially placed across two-thirds of the channel, at the designriffle crest location, by stapling them to 2x4 timber supports.
Photograph 14: 11-Oct-05 1025h
The impermeable liner and accompanying non-woven geotextilewere initially placed across two-thirds of the channel, at the designriffle crest location, by stapling them to 2x4 timber supports.
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Photograph Description
Photograph 15: 11-Oct-05 1045h
The liner material was tied into the RDB by laying it against thebank upstream of the riffle and placing granular fill on top of it.
Photograph 16: 11-Oct-05 1211h
Rock riprap was placed at the crest of the upstream riffle. Tworows of rock were placed and knitted together by selecting piecesthat interlocked in the best possible fashion.
Photograph 17: 11-Oct-05 1212h
At the downstream end of the instream diversion, clean water canbe observed flowing against the LDB, through turbid, pondedwater at the downstream end of the work area.
Photograph 18: 11-Oct-05 1243h
Continued placement of 150 mm minus granular fill material “inthe dry” outside of the instream diversion area.
Photograph 19: 11-Oct-05 1255h
Instream diversion as viewed from downstream.
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Photograph Description
Photograph 20: 11-Oct-05 1258h
View from upstream of first riffle, showing rock riprap being placedat the riffle crest elevation.
Photograph 21: 11-Oct-05 1404h
Large diameter granular material excavated from the Hinton EastHardisty sewer construction project. This material was beingconsidered as 350 mm minus granular fill to provide an armorlayer for the downstream riffle surface. This material source wasultimately not used as material of sufficient quantity and qualitywas not available during the riffle construction period.
Photograph 22: 11-Oct-05 1416h
Large diameter granular material excavated from the Hinton EastHardisty sewer construction project. This material was beingconsidered as 350 mm minus granular fill to provide an armorlayer for the downstream riffle surface. This material source wasultimately not used as material of sufficient quantity and qualitywas not available during the riffle construction period.
Photograph 23: 11-Oct-05 1427h
Large diameter granular material from the West Central yard inHinton. This material was being considered as 350 mm minusgranular fill to provide an armor layer for the downstream rifflesurface. This material source was ultimately not used as materialof sufficient quantity and size was not available during the riffleconstruction period.
Photograph 24: 11-Oct-05 1436h
Large diameter granular material from the West Central pit acrossthe Athabasca River from Hinton. This material was beingconsidered as 350 mm minus granular fill to provide an armorlayer for the downstream riffle surface. This material source wasultimately not used as material of sufficient size was not availablefrom this source.
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Photograph Description
Photograph 25: 11-Oct-05 1439h
Large diameter granular material from the West Central pit acrossthe Athabasca River from Hinton. This material was beingconsidered as 350 mm minus granular fill to provide an armorlayer for the downstream riffle surface. This material source wasultimately not used as material of sufficient size was not availablefrom this source.
Photograph 26: 11-Oct-05 1440h
Large diameter granular material from the West Central pit acrossthe Athabasca River from Hinton. This material was beingconsidered as 350 mm minus granular fill to provide an armorlayer for the downstream riffle surface. This material source wasultimately not used as material of sufficient size was not availablefrom this source.
Photograph 27: 11-Oct-05 1459h
End of the first day of construction, showing progress onplacement of 150 mm minus granular fill and riffle crest rockriprap.
Photograph 28: 12-Oct-05 0949h
Typical 150 mm minus granular fill material in the stockpile onsite.
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Photograph Description
Photograph 29: 12-Oct-05 1043h
View of Riffle #9 from RDB, prior to placement of any boulders formaintenance.
Photograph 30: 12-Oct-05 1019h
View of Riffle #8 from RDB, prior to placement of any boulders formaintenance.
Photograph 31: 12-Oct-05 1024h
View of Riffle #8 from RDB, during placement of boulders formaintenance.
Photograph 32: 12-Oct-05 1049h
View of Riffle #8 from RDB, after placement of boulders formaintenance.
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Photograph Description
Photograph 33: 12-Oct-05 1245h
Large diameter granular material from the Town of Hintonwaste/borrow stockpile. This material was being considered as350 mm minus granular fill to provide an armor layer for thedownstream riffle surface. This material source was ultimately notused as material of sufficient size was not available from thissource.
Photograph 34: 12-Oct-05 1359h
View of Riffle #2 from RDB, prior to placement of any boulders formaintenance.
Photograph 35: 12-Oct-05 1555h
Placement of rock riprap at the lower rock vortex weir.
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Photograph Description
Photograph 36: 12-Oct-05 1702h
End of the second day of construction, showing progress onplacement of 150 mm minus granular fill, riffle crest rock riprapand vortex weir rock riprap.
Photograph 37: 12-Oct-05 1723h
End of the second day of construction, showing progress onplacement of 150 mm minus granular fill, riffle crest rock riprapand vortex weir rock riprap.
Photograph 38: 12-Oct-05 1744h
Large diameter granular material from the Border Paving HintonPit. This material was ultimately selected as 350 mm minusgranular fill to provide an armor layer for the downstream rifflesurface.
Photograph 39: 13-Oct-05 0931h
First load of 350 mm minus granular fill arriving on site. This loadappears slightly undersized with a higher than acceptable finescontent.
Photograph 40: 13-Oct-05 0933h
Additional loads of 350 mm minus granular fill from the BorderPaving pit. The material size is up to acceptable levels, thoughstill marginal.
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Photograph Description
Photograph 41: 13-Oct-05 0940h
Additional loads of 350 mm minus granular fill material arriving onsite from the Border Paving pit. This material is well into theacceptable size range.
Photograph 42: 13-Oct-05 1017h
Additional loads of 350 mm minus granular fill material arriving onsite from the Border Paving pit. This material is well into theacceptable size range and is representative of the bulk of thematerial placed in the channel.
Photograph 43: 13-Oct-05 1141h
Installation of the downstream sediment trap on Hardisty Creek atSwitzer Avenue.
Photograph 44: 13-Oct-05 1141h
Installation of the downstream sediment trap on Hardisty Creek atSwitzer Avenue.
Photograph 45: 13-Oct-05 1141h
Installation of the downstream sediment trap on Hardisty Creek atSwitzer Avenue.
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Photograph Description
Photograph 46: 13-Oct-05 1142h
Installation of the downstream sediment trap on Hardisty Creek atSwitzer Avenue.
Photograph 47: 13-Oct-05 1303h
Placement of material and grade survey on the lower vortex weirat the riffle construction.
Photograph 48: 13-Oct-05 1303h
Placement of material and grade survey on the lower vortex weirat the riffle construction.
Photograph 49: 13-Oct-05 1609h
End of the third day of construction, showing progress onplacement of 150 mm minus granular fill, riffle crest rock riprapand vortex weir rock riprap.
Photograph 50: 13-Oct-05 1609h
End of the third day of construction, showing progress onplacement of 150 mm minus granular fill, riffle crest rock riprapand vortex weir rock riprap.
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Photograph Description
Photograph 51: 13-Oct-05 1610h
Stockpiled 350 mm minus granular fill material for use as channelbed armor.
Photograph 52: 13-Oct-05 1632h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile.
Photograph 53: 13-Oct-05 1633h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile. Water can be seenspilling through the non-woven geotextile on the downstream side.
Photograph 54: 13-Oct-05 1633h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile. Water can be seenspilling through the non-woven geotextile on the downstream side.
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Photograph Description
Photograph 55: 13-Oct-05 1633h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile.
Photograph 56: 13-Oct-05 1634h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile.
Photograph 57: 14-Oct-05 0813h
Installation of buried temporary diversion pipe in the instreamdiversion, to allow fill placement along the LDB of the channel. A500 mm diameter, corrugated “Big O” pipe was used.
Photograph 58: 14-Oct-05 0818h
Inlet of the buried diversion pipe.
Photograph 59: 14-Oct-05 0819h
Mainly dry channel along the diversion pipe, prior to placement of150 mm minus granular fill material.
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Photograph Description
Photograph 60: 14-Oct-05 0821h
Placement of 150 mm minus granular fill material and live willowstakes along the downstream diversion pipe.
Photograph 61: 14-Oct-05 0827h
Placement of 150 mm minus granular fill material and live willowstakes along the downstream diversion pipe.
Photograph 62: 14-Oct-05 0832h
Placement of 150 mm minus granular fill material and live willowstakes along the downstream diversion pipe. Also visible ispolyethylene sheeting that was placed on the creek bank at theoutlet of two 4-inch pumped diversion hoses.
Photograph 63: 14-Oct-05 0845h
Inlet of diversion pipe, and 150 mm diameter granular fill materialplaced above the pipe inlet.
Photograph 64: 14-Oct-05 0847h
Inlet of diversion pipe, and 150 mm diameter granular fill materialplaced above the pipe inlet.
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Photograph Description
Photograph 65: 14-Oct-05 0848h
Inlet of diversion pipe, and 150 mm diameter granular fill materialplaced above the pipe inlet.
Photograph 66: 14-Oct-05 0848h
Inlet of diversion pipe, and 150 mm diameter granular fill materialplaced above the pipe inlet.
Photograph 67: 14-Oct-05 0928h
The diversion pipe inlet was extended upstream by placing anadditional section of pipe, to allow placement of additional fillmaterial in this area.
Photograph 68: 14-Oct-05 0928h
The diversion pipe inlet was extended upstream by placing anadditional section of pipe, to allow placement of additional fillmaterial in this area.
Photograph 69: 14-Oct-05 0938h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile.
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Photograph Description
Photograph 70: 14-Oct-05 0938h
Rock riprap and 350 mm minus granular material stockpiled atRiffle #9 to allow future maintenance/improvement of the riffle. 3pieces of 750 mm rock riprap and 2.5 m3 of 350 mm minusgranular material were placed at this location.
Photograph 71: 14-Oct-05 0939h
350 mm minus granular material stockpiled at Riffle #8 to allowfuture maintenance/improvement of the riffle. 3 pieces of 750 mmrock riprap and 2 m3 of 350 mm minus granular material wereplaced at this location.
Photograph 72: 14-Oct-05 0940h
350 mm minus granular material stockpiled at Riffle #7 to allowfuture maintenance/improvement of the riffle. 2 m3 of 350 mmminus granular material were placed at this location.
Photograph 73: 14-Oct-05 0941h
350 mm minus granular material stockpiled at Riffle #6 to allowfuture maintenance/improvement of the riffle. 6 m3 of 350 mmminus granular material were placed at this location.
Photograph 74: 14-Oct-05 0942h
350 mm minus granular material stockpiled at Riffle #5 to allowfuture maintenance/improvement of the riffle. 3 m3 of 350 mmminus granular material were placed at this location.
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Photograph Description
Photograph 75: 14-Oct-05 0943h
350 mm minus granular material stockpiled at Riffle #4 to allowfuture maintenance/improvement of the riffle. 6 m3 of 350 mmminus granular material were placed at this location.
Photograph 76: 14-Oct-05 0944h
350 mm minus granular material stockpiled at Riffle #3 to allowfuture maintenance/improvement of the riffle. 6 m3 of 350 mmminus granular material were placed at this location.
Photograph 77: 14-Oct-05 0951h
View downstream on Hardisty Creek from just below SwitzerDrive. This series of photos was taken to prepare for potentialfuture restoration of the reach between Switzer Avenue and theWest Fraser property.
Photograph 78: 14-Oct-05 0952h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 79: 14-Oct-05 0953h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
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Photograph Description
Photograph 80: 14-Oct-05 0953h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 81: 14-Oct-05 0956h
View upstream on Hardisty Creek from the location of thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 82: 14-Oct-05 0957h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 83: 14-Oct-05 0957h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 84: 14-Oct-05 0958h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
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Photograph Description
Photograph 85: 14-Oct-05 0958h
Fill material in LDB of Hardisty Creek, just below the precedingphotograph. This series of photos was taken to prepare forpotential future restoration of the reach between Switzer Avenueand the West Fraser property.
Photograph 86: 14-Oct-05 0959h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 87: 14-Oct-05 1000h
Seepage zone in LDB of Hardisty Creek, just below the precedingphotograph. This seep did not appear to be natural and should beinvestigated prior to any stream restoration work in this area. Thisseries of photos was taken to prepare for potential futurerestoration of the reach between Switzer Avenue and the WestFraser property.
Photograph 88: 14-Oct-05 1001h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
Photograph 89: 14-Oct-05 1002h
View downstream on Hardisty Creek from just below thepreceding photograph. This series of photos was taken toprepare for potential future restoration of the reach betweenSwitzer Avenue and the West Fraser property.
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Photograph Description
Photograph 90: 14-Oct-05 1003h
View downstream on Hardisty Creek from just below thepreceding photograph. A trash pump / water intake is visible onthe LDB. This series of photos was taken to prepare for potentialfuture restoration of the reach between Switzer Avenue and theWest Fraser property.
Photograph 91: 14-Oct-05 1004h
View downstream on Hardisty Creek from just below thepreceding photograph. The West Fraser mill boundary fence isvisible in the downstream portion of the photograph. This seriesof photos was taken to prepare for potential future restoration ofthe reach between Switzer Avenue and the West Fraser property.
Photograph 92: 14-Oct-05 1004h
Trash pump / water intake is located on the LDB of HardistyCreek, just upstream of the West Fraser property. This series ofphotos was taken to prepare for potential future restoration of thereach between Switzer Avenue and the West Fraser property.
Photograph 93: 14-Oct-05 1004h
Fill on the RDB of Hardisty Creek, just upstream of the WestFraser property. This series of photos was taken to prepare forpotential future restoration of the reach between Switzer Avenueand the West Fraser property.
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Photograph Description
Photograph 94: 14-Oct-05 1011h
Check on the sediment trap on Hardisty Creek at Switzer Drive.Rising water levels in the pond are due to deposition of leavesand sediment on the non-woven geotextile.
Photograph 95: 14-Oct-05 1035h
Inlet of the instream diversion, showing pumped diversion lines.
Photograph 96: 14-Oct-05 1209h
Outlets of piped instream diversion and pumped diversions.
Photograph 97: 14-Oct-05 1313h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
Photograph 98: 14-Oct-05 1313h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
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Photograph Description
Photograph 99: 14-Oct-05 1314h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
Photograph 100: 14-Oct-05 1314h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
Photograph 101: 14-Oct-05 1315h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
Photograph 102: 14-Oct-05 1316h
Sediment entering the channel from the first flush of well-gradedarmor material.
Photograph 103: 14-Oct-05 1318h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions.
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Photograph Description
Photograph 104: 14-Oct-05 1339h
Pumped diversion hoses were placed on completed armor layer toenhance movement of fines into the interstices between largerrock fractions. This photograph also shows the lower vortex weir.
Photograph 105: 14-Oct-05 1351h
Remaining breach in the riffle that allows flow through the pipeddiversion.
Photograph 106: 14-Oct-05 1405h
Inlet of instream diversion pipe prior to placement of material toblock the inlet.
Photograph 107: 14-Oct-05 1406h
Inlet of instream diversion pipe during placement of material toblock the inlet.
Photograph 108: 14-Oct-05 1413h
Inlet of instream diversion pipe after placement of material toblock the inlet. Note the increase in upstream pond water surfaceelevation after less than seven minutes. The non-wovengeotextile material was placed over the inlet prior to placement of150 mm minus granular fill material, to prevent loss of fill into thepipe inlet and potential failure of the riffle structure.
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Photograph Description
Photograph 109: 14-Oct-05 1422h
Rapid placement of 150 mm minus granular fill material and rockriprap material on the riffle crest, as the upstream pond elevationincreased.
Photograph 110: 14-Oct-05 1429h
Visible movement of clean water through the Hardisty Avenueculverts into the upstream pond.
Photograph 111: 14-Oct-05 1429h
Visible movement of clean water through the Hardisty Avenueculverts into the upstream pond.
Photograph 112: 14-Oct-05 1430h
Placement of live willow plantings along the borders of theupstream pond.
Photograph 113: 14-Oct-05 1430h
Placement of live willow plantings along the borders of theupstream pond.
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Photograph Description
Photograph 114: 14-Oct-05 1431h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle.
Photograph 115: 14-Oct-05 1439h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle, and first spill of water over the crest of the riffle.
Photograph 116: 14-Oct-05 1440h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle, and continued spill of water over the crest of the riffle.
Photograph 117: 14-Oct-05 1453h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle, and movement of water down the riffle.
Photograph 118: 14-Oct-05 1456h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle, and movement of water down the riffle.
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Photograph Description
Photograph 119: 14-Oct-05 1457h
Rapid placement of 350 mm minus armor layer below the crest ofthe riffle, and movement of water down the riffle.
Photograph 120: 14-Oct-05 1535h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.
Photograph 121: 14-Oct-05 1550h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.
Photograph 122: 14-Oct-05 1550h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.
Photograph 123: 14-Oct-05 1654h
Natural riffle located just upstream of Hardisty Avenue, showingsimilar geometry and bed material characteristics to completedriffle.
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Photograph Description
Photograph 124: 14-Oct-05 1658h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.
Photograph 125: 14-Oct-05 1659h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.Submergence of the Hardisty Avenue culverts is visible.
Photograph 126: 14-Oct-05 1659h
View of completed riffle from upstream, showing clean waterentering the upstream pool from the Hardisty Avenue culverts.
Photograph 127: 14-Oct-05 1702h
Inlet of larger Hardisty Avenue culvert, showing the extent ofbackflooding during low flow.
Photograph 128: 14-Oct-05 1702h
Inlet of larger Hardisty Avenue culvert, showing the extent ofbackflooding during low flow.
APPENDIX III
FISHERIES INFORMATION COLLECTEDPRIOR TO CONSTRUCTION
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Table III.1 – Record of Fish Collected, Evening of 10 October 2005
Samples were collected at Switzer Drive Bridge, downstream of the sediment trap, unlessotherwise noted. Samples were tested using a Lamotte 2020 Turbidity Meter.
and FSS of less than zero, and this indicates that it
is likely underballasted. However, the ballasting
may be adequate because of the fact that the LWD
does not appear to have moved during the high
water events of June 2005, and that there was
significant sediment deposition around the
structure at that time, meaning that it is currently
embedded in the creek bed. The reported root wad
diameter was 3.5 m, but an effective diameter of 1.8 m was used for calculation purposes.
Summary
A summary of the calculated Factors of Safety for Buoyancy and Sliding for each LWD structure
is provided in Table V9, along with comments and recommendations for each structure. Overall,
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stability was confirmed for 10 of the 20 LWD structures. The remaining structures had calculated
Factors of Safety for Buoyancy, FSB, of between 0.4 and 1.1. LWD structures with FSB values of
1.0 or less by definition will have Factors of Safety for Sliding, FSS, of less than zero. These
structures may be underballasted; however, it is possible in some cases that the calculated values
are overly conservative. This is because the ballasting calculations assume full submergence of
the LWD structures, and the relatively low water depths during flood events on Hardisty Creek
mean that logs may not be fully submerged. There did not appear to be any movement of these
structures during the high water events of June 2005. For these structures, dimensions and
calculations should be confirmed after an additional inspection to confirm the parameters used in
the assessment, and additional ballasting should be considered if required.
Table V9 – Summary of Calculated Factors of Safety for LWD Structures
LWDStructure
Factor ofSafety forBuoyancy,
FSB
Factor ofSafety forSliding,
FSS
Comments and Recommendations
1 0.4 -2.5 Confirm dimensions; may be underballasted.
2 4.4 3.1 Stability confirmed.
3 2.2 n/a Stability confirmed.
4 2.3 1.3 Stability confirmed.
5 1.6 1.6 Likely stable, FS > 2.0 would be preferred.
6 2.5 n/a Stability confirmed.
7 0.9 -0.1 Confirm dimensions; may be underballasted.
8 3.7 2.1 Stability confirmed.
9 2.3 n/a Stability confirmed.
10 0.7 n/a Confirm dimensions; may be underballasted.
11 1.1 0.3 May be underballasted but appeared stable in June 2005.
12 1.0 -0.1 Confirm dimensions; may be underballasted.
13 1.8 n/a Likely stable, FS > 2.0 would be preferred.
14 0.6 -2.3 Confirm dimensions; may be underballasted.
15 0.7 -0.8 Confirm dimensions; may be underballasted.
16 2.2 3.3 Stability confirmed.
17 0.9 -0.4 Confirm dimensions; may be underballasted.
18 0.7 -1.4 Calculations say underballasted, but currently embedded in bed.
19 0.6 n/a Confirm dimensions; may be underballasted.
20 3.2, 2.2, 1.3 2.4, 1.2, 1.1 Likely stable, FS > 2.0 would be preferred.
APPENDIX VI
CONSTRUCTIONSURVEY DATA
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Prior to construction, temporary benchmarks were established and surveyed to assist with the
final field-fit design and construction of the backflooding riffle. Surveys were not referenced to a
geodetic datum and lateral control was based on cloth-tape distance measurements. This method
was sufficient for layout of the rock fill structures.
Vertical Control Surveys
Point BS HI FS Elev Notes
Lg Culv Inv 2.129 102.129 - 100.000 Invert of Large Culvert Outlet; assumed elevationLg Culv Crn - 0.487 101.642 Crown of Large Culvert OutletSm Culv Inv - 1.878 100.251 Invert of Small Culvert OutletSm Culv Crn - 0.684 101.445 Crown of Small Culvert Outlet
Pool - 2.283 99.846 Water surface elevation in downstream pool
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PRE-CONSTRUCTION SURVEY AND DESIGN ELEVATIONS
Boxed entries denote final elevation checks during construction. Other checks were performedas fill material was being placed.
Top of 350mm MinusTop of 150mm MinusPre-Construction Bed
APPENDIX VII
JULY 2006 INSPECTIONAND PHOTO SURVEY
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The project site was visited by Nathan Schmidt on 1 July 2006 and photographs of key features
were taken. These are presented below, with comments. It is understood that the spring runoff in
2006 was not high and that the constructed riffle has not experienced deep or rapid flows.
Photo 1 – Riffle 1 from RDB. Photo 2 – Backflood pool from RDB.
Photo 3 – Backflood pool from upstream. Photo 4 – Riffle 1 from LDB.
Photo 5 – Backflood pool from LDB. Photo 6 – Excavated holes at Riffle 1 LDB.
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Photo 7 – Riffle 1 front face from downstream. Photo 8 – First grade control below Riffle 1from LDB.
Photo 9 – Second grade control below Riffle 1from LDB.
Photo 10 – Successful willow staking in secondgrade control.
Photo 11 – Successful willow staking alongRDB.
Photo 12 – Successful willow staking alongRDB.
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Photo 13 – First grade control below Riffle 1from RDB.
Photo 14 – Second grade control below Riffle 1from RDB.
Photo 15 – Toe of large diameter fill from RDB.
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Photo 16 – Riffle 2 from RDB. Photo 17 – Riffle 1 viewed from Riffle 2.
Photo 18 – Successful willow staking on LDBbelow Riffle 2.
Photo 19 – Successful willow staking on LDBbelow Riffle 2.
Photo 20 – Riffle 3 from RDB. Photo 21 – Riffle 3 and reconstructed RDBfrom downstream.
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Photo 22 – View upstream from below Riffle 3. Photo 23 – Riffle 1 from RDB downstream.
Photo 24 – Riffle 1 from RDB downstream. Photo 25 – Crest and face of Riffle 1 from RDB.
APPENDIX VIII
REVIEW COMMENTS ONDRAFT REPORT
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The draft report for this project was issued on 14 March 2006 and review comments were
received from Mr. Rich McCleary of Foothills Model Forest on 30 May 2006. Annotated
comments are provided below:
-Comment: The report provided rationale for adjustments that were made to the initialproject plan and thoroughly described the construction procedure. My questions mainlypertain to some aspects of the final layout and follow-up including monitoring.
Comment: Town of Hinton needs to send completed forms to Alberta Environment.
1 Response: It is assumed that this was done using the Certificate of Completion includedin Appendix I of the draft and final reports. If not, this should be done as soon aspossible.
Comment: Did Nathan survey and post-construction cross-sections for monitoring? Ifso, can the FMF get a copy of that data for future monitoring?
2 Response: Cross-sectional survey data have been provided in Appendix VI of thisreport.
Comment: Page i – need to add verb in 5th line from bottom (i.e. “cross-section wasreduced”).3Response: This edit has been made in the final report.
Comment: page ii – At end of second paragraph, consider adding: Monitoring shouldevaluate in-filling of culvert outlet pool and scour of small material from the face of theriffle.4
Response: This edit has been made in the final report.
Comment: Town of Hinton needs to arrange Phase I Environmental Site Assessment asper page iv.
5 Response: It is strongly recommended that potential contamination of the area belowSwitzer Drive be assessed prior to any construction.
Comment: A number of changes to the original plan were made to preserve the poolcreated by the damming effect upstream of riffle #2. Does Nathan expect that this poolwill be maintained by scouring over the longer term? Is there any need of a gradecontrol structure at the transition between the tail of riffle 1 and the upstream pool of riffle2?
6
Response: During the floods of June 2005, downstream movement of fine gravelsresulted in deposition along the margins of the channel but did not cause pools abovethe riffles to infill. During high flows, the rise in elevation away from the channelcenterline at each riffle concentrates the flow in the center of the channel, increasesvelocities in that area and may create a vortex that scours the pool and maintains itsdepth. Thus it is expected that pools will be maintained over the long term.Response: With regards to a grade control structure at the transition from the tail ofriffle 1 and the upstream pool of riffle 2 (the area shown in Photo 16 of Appendix VII), itwould certainly not hurt to provide some sort of grade control in this area; however, it isexpected that the backwater provided by the downstream riffle will control water depthand flow velocity in this area during high flows and thus limit scour potential. This areashould be a focus of monitoring, especially after high flow events.
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Comment: Page 5 – riffle armoring: Are mean flow velocities from Table 1 adjusted for7% slope of riffle verses 5% slope in initial design? Is this an important consideration inthe design?
7 Response: Yes, the mean flow velocities in Table 1 considered the as-built 7% riffleslope. The design is not very sensitive to the slope changes. A check on thecalculations indicates that decreasing the slope to 5% would increase the design flowdepths by approximately 7%, decrease the mean flow velocities by approximately 12%,and increase the critical flow velocities presented in Table 1 by approximately 1%.
Comment: Page 5 – riffle armoring: Are the particles in the vicinity of the vortex weirslarge enough to compensate for increased scour around key boulders due size of rocksand flow constriction between boulders? The elevation of the boulder top in the vortexweirs increased towards channel margins and out onto floodplain. This seems similar tothe configuration used in 2004 that contributed to erosion of backside of riffles. Is this anissue?
8
Response: The vortex weirs are shown in Photos 47 and 48 of Appendix II and Photos8, 9, 13 and 14 of Appendix VII. Flow around the protruding boulders of the weir will becomplex and it is expected that during flood events more of the smaller bed materialfractions will be removed than at other locations. However, this situation is much lesscritical than that of the downstream riffles during the 2005 floods, for the followingreasons:
The likely mechanism for movement of individual boulders at the lower riffles duringthe 2005 floods was scour of downstream material and then shifting due tounbalanced hydrostatic forces. The downstream material was substantially smallerand more scour-prone than the 350 minus material that was placed duringconstruction of the upper riffle.
The vortex weirs were constructed in two layers, with completely buried footerboulders (currently not visible) located downstream and supporting the half-buriedtop layer of boulders. The upper layer of boulders occupies less than 50% of thechannel width at the bed, in contrast to the downstream riffles where the upper layeroccupies close to 100% of the channel width at the bed. This will create less of a“plunging” flow pattern, as occurs at the downstream riffles, as flow passes throughthe weir. Local flow velocities due to flow constriction at peak discharges areexpected to increase by less than 50%, and local scour may occur downstream ofthe weir. However, they are expected to increase local bed roughness (increasingflow depth and decreasing velocity) and limit upstream scour.
Comment: The Foothills Model Forest is planning to continue with floodplain restorationin Kinsmen Park during summer of 2007. This entails construction of a fabricencapsulated soil lift which would increase the elevation of the floodplain by 15-20 cm.Is the left downstream side of the backflooding area appropriate for this activity? Thework would take place outside the boundary of the new channel, as indicated by thewillows that were planted in a trench.
9 Response: Either bank would be appropriate, though as noted in discussions a keyfactor may be to do the work in an area that is likely to be sheltered from human traffic.Two additional factors to consider are:
The channel bankfull width should not be reduced to less than 12 m.
The elevation of the local water table should be determined to ensure that adequatewater supply is available for vegetation.
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Comment: Who does Nathan recommend should complete the additional inspection ofthe LWD structures to confirm whether or not additional ballast is required?
10
Response: The additional inspection/assessment could be done during the next phaseof work at the project. As noted in Appendix V, calculated factors of safety may beconservative and some judgment might be applied to the calculated values based onlocal conditions. The assessment considered a design mean flow velocity of 2.0 m/s andmean flow depth of 0.68 m. Factors to consider include:
The calculations assume full submergence of woody debris, while the design meanflow depth of 0.68 m may not allow full submergence. This would reduce buoyantand drag forces on woody debris.
Actual flow velocities on LWD structures located in pools or in sheltered areas maybe lower than the calculated mean channel velocity of 2.0 m/s. This would reducedrag forces on woody debris.
Comment: Are there any recommended procedures for future monitoring? i.e. Howmany cross-sections should be surveyed? Should we use D50 to track changes in bedmaterial size down backside of riffle? The bed of the stream makes a subtle transition tothe floodplain. What should we use to delineate the outer boundaries of the channelwhen completing the bed material monitoring?
11
Response: Recommendations for future monitoring include:
A consistent roster of locations should be defined for long-term monitoring. The siteis sufficiently small that it should be possible to monitor all riffle crests, locations ofLWD and boulder structures, and bed and bank characteristics at selected locations.It is recommended that photographs be taken at key locations from a consistent pointof view to qualitatively track changes.
Cross-section surveys may be limited to riffle/weir crests and perhaps representativetransects across pools or riffles. In particular, channel bank formation upstream ofriffles (as observed in June 2005) may be of interest. A channel thalweg surveyalong the length of the reach would be a good way to track scour, deposition andpotential settlement of weir crests.
D50 could be used to track changes to bed material along the backside of riffles. Atriffle #1, the bed material appears to be well-graded with good particle embedment,but it is expected that some armoring will occur during flood events. Monitoring in thisarea and any others of interest is recommended, using a quantitative method suchas pebble counting or grid methods. Photographs should be taken to compile avisual record at each location.
The streambed makes a subtle transition to floodplain on the lower face of riffle #1. Itis expected that over time, deposition of sediment and organics may create a better-defined boundary. It may be effective to track this by selecting sample locations atvarious distances from the centerline of the channel at this location.